I want to use RSM model to simulate wind tunnel test of buildings. There are some different ways to give epsilon: one is like epsilon=Cu^0.5*k(z)*du/dz(based turbulence equilibrium hypothesis of standard k-epsilon model);

the other is like the style epsilon=Cu^0.75*k^1.5/(Karman Constant*L) or epsilon=Cu^0.75*k^1.5/(Karman Constant*z),

Also fluent suggest give epsilon as epsilon=delta(k)*u/Lx in the case of simulating wind tunnel test.

So,I am not sure how to give epsilon properly and how it effets the results. Any suggestion will be great appreciated.